The arrival of the Silver Ranger in episode 25. Gargotron had the GPX and Flash Rangers down for the count when someone in a trenchcoat shows up, morphs, and beats Gargotron! Okay, so maybe Gargotron didn't have the guy's fight data, but it was still impressive.
Hell, the GPX and Flash Rangers working as a team is a CMOA! Even when working with different-color counterparts, they still compliment each other beautifully.
Daisuke establishing himself as a Badass Normal, fighting Kalderon with a katana!
And of course, the Piece de la resistance: All of the Rangers taking one last shot at Rashon before Sean finishes the job and defeats Rashon on his own.
Sean's Recital of The Doctor's "It is defended" speech, which seals the Rangers' victory and send the Zordonians away.
Queen Eruvanda standing up to Ragnar and declaring she is not his puppet. Granted, she ends up fleeing, but for someone who'd been portrayed with a massive case of The Woman Wearing the Queenly Mask and Broken Bird tendencies, it's downright Badass.
The first time Ritchie fights as a member, beating Turelie in the process.
It seems to be a tradition that the climax of each part contains the most badassery of all the other chapters, and episode 22 is no exception. Let's recap:
Episode 3, "Enter Ragnar". Okay, this one is on the villain's part, but it's a damn good Establishing Character Moment for Ragnar. He's no Rita Repulsa, Lord Zedd or cartoonish supervillain, but a very dangerous and competent antagonist, refusing Sean's duel challenge and subsequently wiping the floor with him.
Marty in SIU, showing that he's worthy of being a Ranger by punching the local Dark Mistress. In the face!
Sean, Maria and Aaron (Mandla) get credit for fighting an Ouroboros Society monster while hungover!
Sean gets another one without throwing a punch (well, kinda). To set it up: Bridget has been bitten in the neck by a Mannequin and he's not in the best of moods. Drake comes and tries to apologize, but then he tries to make Sean an offer to join his group. Sean's response? "Go fuck yourself" and tells him they're not giving up anytime soon.